Shock absorber



Jun1,1937.r ww', EDEL n 2,082,552

SHOCK ABSORBER med Jan. so, 195e w 45 47l \4a \2.r

ffy. 2. W y, 23

6 l, r im M INVENTOR W41 Tf W. Q/fDFL BYl Patented June 1, 1937 snoei; AsoRBER Walter W. Riedel, Dayton, Ohio, assignor to General -Motors Corporation, Detroit, Mich., a. corporation of Delaware ApplicationJanuary 30, 1936, Serial No. 61,446

12 Claims.

This invention relates to improvements in hydraulic shock absorbers.

It is among the objects of the rpresent invention to provide a hydraulic shock absorber with an automatic control device adapted to adjust the shock absorber to vary its resistance tomovements of thelbody and axle of the vehicle in accordance with the-nature of the roadbed over which the vehicle is being operated.

l0 A further object of the present invention is to provide a shock absorber adapted tol resistslight relative movements between the body and axle of a vehicle as well as the more extensive movements thereof.

These and other objects of the presentinvention are attained by providing'a shocky absorber, having a uid displacement chamber and an outlet port therefor, with a valve for controlling the ow of uid through saidport, this valve being 2O' adapted to be actuated by an inertia weight, movably supported within the shock absorber, in accordance with 'accelerations in the movements of the shockabsorber in one direction. A toggle joint is provided in the shock absorber,

2g;v connected with theweight, said toggle joint being adapted to multiplyV the eiect of the weight to adjust said valve into positions in which 4it increasedly restricts the fluid ow from the port.

A spring isinterposed between the valve and the,

toggle joint for yieldably urging the valveaway from the toggle joint and into its normal position in which it closes the port.

Further objects and advantages of the present invention will be apparent fromthe following description, reference being had tothe accompanying drawing, wherein a preferred embodiment of the invention is clearly shown.`

In the drawing: l a Fig. l is a fragmentaryside View of the vehicle chassis, a shock absorber equipped with thepresent invention being shown applied thereto.

Fig. 2 is a longitudinal sectional view taken through the center of the shock absorber.

Fig. 3 is an enlarged fragmentary sectional view showing the inertia weight actuated valve and its spring. y

Referring to the drawing, the numeral 20 designates the frame of the vehicle, which is supported upon the vehicle axle 2| by vehicle springs 22, onlyone of which is shown. For the sake of clearness the-roadwheels of the vehicle are omitted from this View.

'Ihe shockabsorber comprises a casing 23, pro- 55.Viding a uid` reservoir 24- and a cylinder 25.

'I'his cylinder vis in communication with the reservoir through connected passages 26 and 21.

A'rocker shaft 30 is'journalled transversely of* thef shock absorberfhousing, one` endof saidA rocker shaft extending to the outside of the` 5 housing and having the shock absorber operating arm 3| attached thereto. The free end of' this arm has one end of a link 32 connected thereto, thel opposite end: of the link being anchored toIl the axle 2| `of the vehicle as at 33. Within the shock absorber an operating cam 34 is secured to the rocker shaft v3|), this arm engaging a piston 40 slidably carried within, the cylinder 25. 'A` spring` 4|, interposed between the bottom end of the cylinder 25 and the piston, maintains the l5M1 piston in engagement with the operating cam till;4 Piston 40 has a passage 45 providing for' the transfer of iluid from one side of the piston to the other. An annular valve seat 46 surrounds the passage 45 and is adapted to be'engaged byY the intake valve 41, this valve being urged normally to engage the seat 46 by the spring i3-in-v terposed between the valve and a cage member 49.- This cage member ismaintained in contact= with the interiorf'surface of the head of piston 40 by the spring 4|. A central passage in valve 41 ismnormally maintained closed by they pressure release valve 50 urged into engagement with the one surface of the intake valve 41 by a spring 5|, one end of which engages the` intake valve 41,v the other an abutment collar 52. secured to the stem portion of the valve 50.

The passage 21, in communicationv with" the interior of the cylinder 25 through passage 26, is also provided withan annular ridge. 6D forming, a valve-seat adapted to be engaged by the static, valve 6|, side openings|62 in the casing providing for iluid fiow from `the valve 6| after it has been moved fromv its seat 6U. l Acover plate 10 is secured to the shock absorber casing by screws 1|. This cover` plate has a depending ear 13 carrying a pin 1.44 upon which the inertia mass or weight 15 is pivotally supported. A screw 16 threadedly carried `bythe. cover 10 provides an adjustable stop for the in- 4'5` ertia weight 15, a bracket 11, secured to said.` weight, being adapted to engage with screw 16. A spring is interposed between bracket 11 onI the weight 15 and a similar bracket 8| .clamped between the cover 10 and the shock .absorber 50 casing. This spring yieldably maintainsr the weight 15 in normal position as shown inFvig. 2, in which 'position bracket 11 Vengagesscrew 16.

A toggle joint comprising links and 9| hingedly secured together by the pivot pin 92 is provided in the shock absorber, the one end of link 9D being pivotally secured to an ear 93 formed on the cylinder portion 25 of the shock absorber. A member 94 attached to the weight engages the pivot pin 92 of the toggle joint whereby the toggle joint is operatively connected with the weight-15. A reduced end 95 of the toggle link 9| extends into the recessed, outer end of the valve 6|. Two washers 96 are threaded upon the link 9| of the toggle, forming one abutment for the spring 91 which also engages the valve 6| normally urging it away from the end 95 of the link 9| and into' engagement with the valve-seat 6|) normally to close the port formed by the passage 21 in com munication with the interior of the cylinder 25. K

The shock absorber just described functions in the following manner: i E

Supposing a roadwheel of the vehicle strikes an obstruction in the roadbed, causing the axle 2| to be thrust upwardlyftoward the frame 29. This results in a clockwise movement of the arm 3| and a similar movement of the operating cam 34. As the cam 34 rotates clockwise within the shock absorber, spring 4| tends to urge piston 40 to follow the movement of cam 34, resulting in a movement of the piston toward the left as regards Fig. 2. Under `these circumstances fluid will move valve 41 from engagement with its seat 46 to establish a substantillay free flow of fluid from the reservoir 24 throughvthe piston passage 45 intothe interior of the cylinder 25. When the axle 2| is moved away from the frame 20, due to the return of the spring 2| to its normal load position, the reverse movement of the shock absorber obtains, resulting in a movement of the arm 3| and cam 34 counter-clockwise and piston 49 toward the right as regards Fig. 2. Now pressure is exerted upon the fluid within the cylinderv 25, which pressure, when attaining a predetermined value, will urge valve 5| from its seat 60 against the effect of spring 91, thus establishing arestricted flow of fluid past the valve 6| through the side openings 62 into the reservoir. This restriction to the fluid flow causes the shock absorber to provide resistance to the movement of the axle 2| away from frame 20. If valve 6| cannot properly relieve excessive pressures created within the cylinder 25 by movement of,

the piston 49 toward the right, then valve 50 is moved from its engagement with valve 41 against the effect of spring 5| to establish an additionalflow of fluid from the cylinder 25 through the central passage of valve 41 and out izlanough the piston passage 45 into the reservoir Now supposing the vehicle frame 20 is moving 4 upwardly away from the axle 2| at an accelerated rate, causing counterclockwise rotationof the arm 3| and cam 34 and a movement of the piston 40 toward the right. within the cylinder 25, when attaining a proper value, will move valve 6| from-its seat to establish a restricted flow of fluid from the cylinder 25 through passages 26 and 21 past the valve 6| into the reservoir. This restriction being substantially low, due to the comparative lightness of spring 96, may not properly restrict the fluid flow to control the acceleratve upward movement of the vehicle body. To provide proper control under these circumstances, applicant provides an inertia weight which, due to its inertia, moves relatively to the shock absorber casing in response to such accelerative upward move- 'wardly, or more specifically,

Naturally pressure ment of the vehicle frame to which the casing is attached, this movement being clockwise as regards Fig. 2. As the weight 15 moves clockwise, it will move the toggle links and 9| toward their aligned position, thus causing the link end to exert pressure upon the valve 6| and move it toward its seat 60. It will of course be understood that valve 6| will engage the end 95 of toggle link 9| when moved by fluid pressure from the cylinder 25' from engagement with its seat 60. The weight 15 is moved downclockwise, proportionately to the acceleration of the upward movement of the shock absorber casing and consequently will urge valve 6| to increase its restriction tothe fluid ow from passage 21 proportionately to such acceleration.

The washers `or collars 96 threaded upon the link 9| of the toggle provide an adjustable abutment for one end of the spring 91 whereby the static load upon the valve 6| may be varied to meet desired conditions. v

From the aforegoing description it may be seen thatpapplicant has provided a shock absorber capable of automatically adjustingl itself in accordance with the nature of the roadbed over which the vehicle is being operated. The shock absorber is also equipped with a springloaded static valve adapted to provide initial restriction to fluid flow whereby the shock absorber will resist slight movements between the axle andframe of the vehicle. This resistance,

however, is automatically increased proportionately with accelerative movements of the shock absorber in one direction by the inertia weight provided in the shock absorber.

Due to the provision of the toggle joint, a small inertia mass may be used to actuate the valve 6| against the comparatively high pressures acting directly upon said valve. Without the provision of the toggle joint a comparatively larger weight would be required to actuate the valve` 6l againstthis comparatively high fluid pressure.

Another feature of applicants device is the provision of a spring which yieldably urges the valve 6l upon its seat whereby to provide initial restriction to fluid flow, necessitating a predetermined pressure to be built up within the shock absorber cylinder 25 before fluid flow is permitted therefrom.

While the embodiment of the present invention constitutes a preferred form, it is to be understood that other forms might be provided, all coming within the scope of the claims which follow.`

What is claimed is as follows:

l. In a hydraulic shock absorber having a fluid displacement chamber provided with an outlet port, the combination with a valve for controlling the flow of fluid from said port; an inertia weight; a toggle joint adapted to be actuated by the weight to adjust said valveto increase its restriction to the fluid flow from said port; and resilient means interposed between the valve and toggle joint, yieldably urging said valve to close the port.

2. In a hydraulic shock absorber having a fluid displacement chamber providedl with an outlet port, the combination with a valve for controlling the flow of fluid from said port; of an inertia weight; a toggle joint normally disengaged from the valve and adapted to be actuated by the weightV to adjust the valve to increase its restriction to fluid flow from said port;

and resilient means interposed between the valve and toggle joint, yieldably urging the valve away from the joint and in port closing position.

3. In a hydraulic shock absorber having a uid displacement chamber provided with an outlet port, the combination with a valve for controlling the flow of fluid from said port; of an inertia weight; levers hingedly secured together, movable by the weight to adjust the valve, and adapted to multiply the force of the weight against the valve to overcome the uid pressure tending to move the valve to open the port; and a spring interposed between the levers and valve and yieldably urging said valve away from said levers and toward the port to close it.

4. In a hydraulic shock absorber having a uid displacement chamber provided with an outlet port, the combination with a valve for controlling the flow of fluid from said port; of an inertia weight movably supported in the shock absorber; a toggle joint interposed between the weight and valve and adapted to multiply the force of the weight acting to urge the valve to increase its restriction to the flow of fluid from the port; and a spring interposed between the toggle and valve, yieldably urging the valve to close the port.

5. In a hydraulic shock absorber having a uid displacement chamber providedwith an outlet port, the combination with a valve for controlling the ow of fluid from said port; of an inertia weight pivotally supported within the shock absorber; an adjustable stop; a spring urging the weight against the stop; and mechanical force multiplying means interposed between the valve and weight, adapted to adjust the valve against the pressure of fluid acting upon it; and a spring interposed between said means and valve yieldably urging the Valve to close the port.

6. In a hydraulic shock absorber having a fluid displacement chamber provided with an outlet port, the combination with a valve for controlling the ow of fluid from said port; of an inertia weight movably supported in the shock absorber; a mechanical force multiplying means attached to the weight and adapted to be engaged by the valve to limit its port opening movement, said means being adapted also to urge the valve toward the port against the eiect of the iiuid pressure acting upon it, in response to movement of the weight relative to the shock absorber; and resilient means yieldably restricting the movement of the valve from port closing position into the mechanical force multiplying means engaging position.

7. In a hydraulic shock absorber having a displacement chamber provided with an outlet port, the combination with an inertia weight; mechanical force multiplying means interposed between the weight and valve adapted to limit the port opening movement of the valve and also adapted to urge the valve to close the port in response to accelerations in the movement of the shock absorber upwardly; and resilient means interposed between the first mentioned means and the valve, yieldably urging the valve to close the port and resisting the movement of the valve toward said first mentioned means.

8. In a hydraulic shock absorber having a displacement chamber provided With an outlet port, the combination with an inertia weight; a toggle joint connected to the weight and adapted to limit the movement of the valve to open the port, said weight acting through said toggle joint to adjust the valve against the fluid pressure acting upon it to open the port, for restricting the flow of uid from the port proportionately to the accelerations in the upward movement of the shock absorber; and a spring supported by the toggle and engaging the valve, yieldably urging it away from the toggle and toward the port to close it.

9. In a hydraulic shock absorber having a displacement chamber provided with an outlet port, the combination with an. inertia weight; a toggle joint, the outer end of one link of which is pivotally secured to the shock absorber, the outer end o-f the other link being adapted to engage the valve to control the opening of the port; means secured to the weight engaging the pivotal connection between the two toggle links; and a spring, one end of which abuts the link more adjacent the valve, the other end engaging said valve, said spring yieldably separating the link and valve and urging the Valve to close the port.

10. In a hydraulic shock absorber having a fluid displacement chamber pro-vided with arr outlet port, the combination with a valve for controlling the flow of fluid from said port; of an inertia weight pivotally supported within the shock absorber; an adjustable stop; a spring normally holding the weight against the stop, a toggle joint comprising two links hinged together, the outer end of one link being pivotally secured to the shock absorber, the outer end of the other link being adapted to engage the valve; means securing the hinged connection of the two links with the weight; and a spring interposed between the toggle link and valve yieldably urging said valve away from said link and into port closing position.

11. In a hydraulic shock absorber having a iiuid displacement chamber provided with an outlet port, the combination with a valve for controlling the flow of fluid from said port; an intertia weight; force multiplying means adapted to be actuated by the weight to adjustA the valve against the effect of fluid pressure thereon; a spring normally, yieldably urging said valve intoI port closing position; and means adjustably carried by the force multiplying means providing an abutment for the spring which may be shifted to vary the effective pressure of the spring upon the valve.

12. In a hydraulic shock absorber having a fluid displacement chamber provided with an outlet port, the combination with a valve for controlling the ow of fluid from said port; an inertia weight; a toggle joint adapted to be actuated by the weight to adjust the valve; an abutment collar adjustably secured to a link of the toggle; and a spring interposed between the collar and valve and yieldably urging the latter normally to close the port.

WALTER W. RIEDEL. 

